Search results for "Dose Fractionation"

Quality of life after pulmonary stereotactic fractionated radiotherapy (SBRT): Results of the phase II STRIPE trial.

2019

Preserving health related quality of life (HRQOL) plays an important role in considering stereotactic body fractionated radiotherapy (SBRT). The prospective monocenter phase II STRIPE trial investigated long-term HRQOL after SBRT, efficacy and toxicity.Patients with ≤2 pulmonary lesions ≤5 cm were treated with 4DPET/CT-based SBRT (3 × 12.5 Gy or risk-adapted 5 × 7 Gy, to 60% isodose). Follow up (FU) was performed 2 and 7 weeks after SBRT, then 3-monthly for 2 years with assessment of response (primary endpoint: 2-year cumulative incidence of local progression (LP); secondary endpoints: local progression free survival (LPFS), overall survival (OS) and toxicity (CTCAE)). Impact of predefined …

Tumor lactate content predicts for response to fractionated irradiation of human squamous cell carcinomas in nude mice

2006

Abstract Background and purpose The present study was performed to test the hypothesis that lactate accumulation correlates with the radioresistance of malignant tumors due to the radical scavenging capacity of lactate or metabolic intermediates of glycolysis, such as pyruvate. Materials and methods Five human head and neck squamous cell carcinoma cell lines (HNSCCs) xenografted in nude mice were treated with a clinically relevant irradiation protocol with 30 fractions within 6 weeks. The radiation dose necessary to locally control 50% of the tumors (TCD 50 ) ranged from 47.4 to 129.8Gy. Concentrations of glucose, lactate, and ATP in viable tumor regions as potential indicators of glycolyti…

Glycolytic metabolism and tumour response to fractionated irradiation.

2009

Abstract Background and purpose To study whether pre-therapeutic lactate or pyruvate predict for tumour response to fractionated irradiation and to identify possible coherencies between intermediates of glycolysis and expression levels of selected proteins. Materials and methods Concentrations of lactate, pyruvate, glucose and ATP were quantified via bioluminescence imaging in tumour xenografts derived from 10 human head and neck squamous cell carcinoma (HNSCC) lines. Tumours were irradiated with 30 fractions within 6weeks. Expression levels of the selected proteins in tumours were measured at the mRNA and protein level. Tumour-infiltrating leucocytes were quantified after staining for CD45…

Weekly Cisplatin and Volumetric-Modulated Arc Therapy With Simultaneous Integrated Boost for Radical Treatment of Advanced Cervical Cancer in Elderly…

2016

Background: To evaluate the feasibility and clinical preliminary results of weekly cisplatin and volumetric-modulated arc therapy to the pelvis with simultaneous integrated boost to macroscopic disease in a cohort of elderly patients. Materials and Methods: Inclusion criteria of this prospective study were age ≥70 years, Karnofsky performance status 70 to 100, locally advanced histologically proven squamous cervical carcinoma, and patients unable to undergo brachytherapy. Radiation doses prescribed were 66 Gy to the macroscopic disease and 54 Gy to the pelvic nodes in 30 fractions. Weekly cisplatin dose was 40 mg/mq. Results: A total of 30 patients were recruited. Median follow-up was 32 mo…

Tumour oxygenation during fractionated radiotherapy--comparison with size-matched controls.

1999

The effect of fractionated irradiation on the oxygenation status of experimental tumours was investigated using polarographic assessment of the pO2 distribution. Since an improvement in tumour oxygenation could simply be the result of tumour shrinkage, a comparison of pO2 readings of untreated size-matched control tumours was performed. Irradiation was carried out using 6 fractions of 6 Gy applied within 11 days. A comparison of polarographic pO2 data with size-matched untreated tumours revealed a significant improvement in oxygenation after the irradiation. The median pO2 was 0.9+/-0.1 mm Hg for unirradiated tumours at a volume of 180 mm3, while the corresponding data for irradiated tumour…

Tumor lymphocyte immune response to preoperative radiotherapy in locally advanced rectal cancer: The LYMPHOREC study

2017

IF 7.719; International audience; Introduction: Some studies have suggested that baseline tumor-infiltrating-lymphocytes (TILs), such as CD8+ and FoxP3+ T-cells, may be associated with a better prognosis in colorectal cancer. We sought to investigate modulation of the immune response by preoperative radiotherapy (preopRT) and its impact on survival in locally advanced rectal cancer (LARC). Materials & Methods: We analyzed data for 237 patients with LARC who received RT. Density of TILS (CD8+ and FoxP3+) in intraepithelial (iTILs) and stromal compartments (sTILs) were evaluated from surgery pathological specimens and biopsies performed at baseline. The primary endpoint was to assess the impa…

Prognostic value of two geriatric screening tools in a cohort of older patients with early stage Non-Small Cell Lung Cancer treated with hypofraction…

2020

Objectives: To investigatewhether assessmentwith two geriatric screening tools shows a correlationwith clinical outcomes of patients aged 65 years or more, with early-stage Non-Small Cell Lung Cancer (es-NSCLC) treated with hypofractionated stereotactic radiotherapy. Methods: FromMarch 2014 to June 2018we retrospectively evaluated 42 patientswith stage I and II lung tumors. Patients were assessed with Charlson Comorbidity Index (CCI) and G8 screening tool. Median age was 74 years (range, 65–91). Stereotactic radiotherapy was performed with Helical Tomotherapy delivering 50–70 Gray (Gy) in 8–10 fractions. Toxicity was evaluated using Common Terminology Criteria for Adverse Events v4.0 criter…

2014

Background and purpose: A substantial reduction of uncertainties in clinical brachytherapy should result in improved outcome in terms of increased local control and reduced side effects. Types of uncertainties have to be identified, grouped, and quantified. Methods: A detailed literature review was performed to identify uncertainty components and their relative importance to the combined overall uncertainty. Results: Very few components (e.g., source strength and afterloader timer) are independent of clinical disease site and location of administered dose. While the influence of medium on dose calculation can be substantial for low energy sources or non-deeply seated implants, the influence…

Analysis and evaluation of periodic physiological organ motion in radiotherapy treatments.

2003

Background and purpose: A system for the detection, measurement and analysis of the periodic physiological organ motion during radiotherapy treatment is proposed and clinically tested in this paper. Material and methods: The procedure is based on the acquisition of fluoroscopic sequences, followed by an automatic detection of the movement using cross-correlations with matched filters. Results: The system generates a probability density function (PDF) of finding a mobile organ in a position at a certain time. The maximum path of the mobile structures can be determined to define the planning target volume (PTV) without ambiguities. Conclusions: Physiological movements can be accurately includ…